Interface analysis and compositional depth profiling by XPS of polymer coatings prepared using ultra-low-angle microtomy

摘要

Conventional rotary microtomy in combination with high-precision, ultra-low-angle sectioning blocks have been used to produce cross-sectional, ultra-low-angle tapers in polymeric coating systems. Tapered samples produced by ultra-low-angle microtomy (ULAM) have been employed in the investigation of intercoat bonding interfaces in multilayer polymeric coatings and for the compositional depth profiling of polymer/polymer + additives systems.X-ray photoelectron spectroscopy (XPS) cross-sectional analysis of a poly(vinylidene difluoride) (PVdF) based topcoat and a poly(urethane) based primer interface exposed by ULAM processing indicates diffusion of fluorine-containing components of the PVdF topcoat formulation into the uppermost nanometres of the underlying poly(urethane) primer. It is demonstrated that a ULAM exposed, cross-sectional multilayer interface, with a taper of <0.05, investigated by high-resolution XPS employing a 15 gin spot-size enables the interface region to be probed at a depth resolution of <20 nm.Depth profiling characterization by XPS of a polyamide powder coating with an organosilane adhesion promoter reveals a silicon concentration gradient within the cured polymer. This result demonstrates that the organosilane preferentially segregates to the surface regions of the cured polymer coating system. Copyright (C) 2004 John Wiley Sons, Ltd.